Tait TM9100 Service Manual

TM9100 Service Manual Power Supply Fault Finding 153
© Tait Electronics Limited August 2005
7 Power Supply Fault Finding
Fault-Diagnosis
Tasks
Fault diagnosis of the power-supply circuitry is divided into six tasks:
■ check inputs to SMPS
■ check 3.3 V supply
■ check linear regulators
■ check power-up
■ check power-up options
The regulators of concern in the third task are those for the 9V, 6V, 3V and
2.5V supplies.
Three Types of Fault Which of the above tasks are applicable depends on the nature of the fault:
■ radio fails to power up
■ power-up option has failed
■ external power at connector has failed
With the first fault, either the radio fails to power up immediately when
power is applied, or it fails to power up when power is applied and the
ON/OFF key is pressed. In this case carry out Task 1 to Task 3. With the
second fault, the radio powers up when the
ON/OFF key is pressed, but not for
a power-up option for which it is configured. In this case carry out Task 4
and Task 5. With the third fault, the external power required at a particular
connector is no longer present. In this case carry out Task 6.

Tait TM9100 Specifications

General

Brand	Tait
Model	TM9100
Category	Radio
Language	English